reworked regex directory structure to match boost requirements.

[SVN r9752]

example/snippets/credit_card_example.cpp

@@ -0,0 +1,69 @@
+/*
+ *
+ * Copyright (c) 1998-2000
+ * Dr John Maddock
+ *
+ * Permission to use, copy, modify, distribute and sell this software
+ * and its documentation for any purpose is hereby granted without fee,
+ * provided that the above copyright notice appear in all copies and
+ * that both that copyright notice and this permission notice appear
+ * in supporting documentation.  Dr John Maddock makes no representations
+ * about the suitability of this software for any purpose.
+ * It is provided "as is" without express or implied warranty.
+ *
+ */
+
+ /*
+  *   LOCATION:    see http://www.boost.org for most recent version.
+  *   FILE         credit_card_example.cpp
+  *   VERSION      3.00
+  *   DESCRIPTION: Credit card number formatting code.
+  */
+
+#include <string>
+#include <boost/regex.hpp>
+
+bool validate_card_format(const std::string& s)
+{
+   static const boost::regex e("(\\d{4}[- ]){3}\\d{4}");
+   return boost::regex_match(s, e);
+}
+
+const boost::regex e("\\A(\\d{3,4})[- ]?(\\d{4})[- ]?(\\d{4})[- ]?(\\d{4})\\z");
+const std::string machine_format("\\1\\2\\3\\4");
+const std::string human_format("\\1-\\2-\\3-\\4");
+
+std::string machine_readable_card_number(const std::string& s)
+{
+   return boost::regex_merge(s, e, machine_format, boost::match_default | boost::format_sed);
+}
+
+std::string human_readable_card_number(const std::string& s)
+{
+   return boost::regex_merge(s, e, human_format, boost::match_default | boost::format_sed);
+}
+
+#include <iostream>
+using namespace std;
+
+int main()
+{
+   string s[4] = { "0000111122223333", "0000 1111 2222 3333",
+                   "0000-1111-2222-3333", "000-1111-2222-3333", };
+   int i;
+   for(i = 0; i < 4; ++i)
+   {
+      cout << "validate_card_format(\"" << s[i] << "\") returned " << validate_card_format(s[i]) << endl;
+   }
+   for(i = 0; i < 4; ++i)
+   {
+      cout << "machine_readable_card_number(\"" << s[i] << "\") returned " << machine_readable_card_number(s[i]) << endl;
+   }
+   for(i = 0; i < 4; ++i)
+   {
+      cout << "human_readable_card_number(\"" << s[i] << "\") returned " << human_readable_card_number(s[i]) << endl;
+   }
+   return 0;
+}
+
+